The present invention relates to a method for manufacturing ceramics with fine hole(s). More specifically, the present invention relates to a method for manufacturing ceramics with fine hole(s) arranged in given place(s) without machining after firing.
Ceramic materials such as silicone nitride, silicone carbide, and partially stabilized zirconia possess excellent properties of heat resistance, abrasion resistance, hardness, corrosion resistance, and the like. Therefore, they are used for machine parts. The field in which ceramic materials are used has been expanding by successive improvements, rationalization of designs, and so on.
Concerning such ceramic parts, there is a demand of forming hole(s) with a given diameter in given place(s). For example, ceramic blades (turbine blades and tubine nozzle) used in a gas turbine have adequate cooling hole(s) for cooling the component and assuring higher reliabilities.
When such a ceramic part having hole(s) is manufactured, the method shown in the process flow chart in FIG. 6 has conventionally been adopted, which comprises the steps of: pressing ceramic powders to give a compact; removing the binder included in the compact by heating; subjecting the compact to cold isostatic pressing (CIP); and making hole(s) by dry machining followed by firing, or firing followed by making holes. In order to make holes, a twist drill, an ultrasonic wave, laser, or the like, has usually been used.
However, such conventional means of making a fine hole with a twist drill, an ultrasonic wave, laser, or the like cannot provide a hole with a diameter equal to or smaller than 0.5 mm, and the depth of the hole is limited to about 10 times as long as the diameter of the hole. Moreover, such means has a problem that a hole in a curved or complex shape cannot be provided.
The present invention aims to provide a method for manufacturing ceramics with fine hole(s) having a diameter equal to or smaller than 0.5 mm and capable of achieving a desired depth and shape of hole(s).